The present invention is directed generally to vehicle tires of the tubeless variety, and more particularly to a safety liner which is inserted inside of the tire. In the event of a blow out, the liner slowly deflates thereby allowing a motorist to safely stop or even continue driving for a short period of time.
Internal safety structures for vehicle tires are well known in the art. These devices are designed to mitigate against the effects of a blowout. For example, U.S. Pat. No. 2,560,609 shows a tire tube which is built into the regular inner tube of the tire, and has facilities for expanding to fill the tire in case the inner tube has become punctured or torn from the effects of a blow out. The internal tube is designed to expand to full inner tube size to keep the tire in up and running condition until a service station is reached.
U.S. Pat. No. 4,008,743 illustrates a pneumatic tire with an internal toroidal safety structure that expands and provides emergency support between the tire tread and the wheel rim if the tire loses inflation pressure. The safety structure has an outer circumferential belt comprising one or more superposed layers of cord reinforced strips, the belt being secured to the safety structure in a relatively narrow central circumferential zone so that radial expansion of the toroidal safety structure is readily accommodated should the tire lose inflation pressure. The belt bears between the inner surface of the tread portion of the tire and the safety structure in the event of tire deflation or underinflation and thus guards against puncture. The safety structure may be an internal inflatable tube or a flexible resilient foam member.
U.S. Pat. No. 4,153,095 shows a pneumatic insert for a pneumatic tire having a generally toroidal shaped hollow member having a pair of annular insert beads with sidewalls extending therefrom joined to an insert crown portion. An annular flap portion is joined to the outer surface of each insert sidewall at the bead area and extends beyond each bead a predetermined amount. The pneumatic insert is disposed in a standard tire and mounted on standard rim. The insert flaps are tucked between the respective insert beads and the bead support surface of the rim to provide a leak-tight seal. When the insert is inflated, the insert beads push the respective tire beads against the rim flange. In one embodiment, the tire is inflated through an air passage member disposed between the tire and insert beads. In another embodiment, the tire is inflated directly through the tire sidewall with a hypodermic needle. The insert inflation chamber and the tire inflation chamber do not communicate and can be inflated to different pressure levels. Other embodiments of the pneumatic insert include fabric reinforcements and/or protective caps.
U.S. Pat. No. 4,216,809 discloses a run-flat insert structure for a pneumatic tire in which the insert structure comprises a homogeneous elastomeric material and is fully enclosed and pneumatically inflated. The insert structure is mounted within the cavity formed by the pneumatic tire and the wheel rim upon which the tire is mounted. The insert structure is shaped and spaced from the interior walls of the tire such that contact between the insert structure and the interior tire walls is minimized during rated load carrying and inflation conditions of the tire. The volume of the insert structure is less than 50% of the volume of the cavity formed by the tire and the wheel rim to thereby assist in avoiding undesirable contact between the insert structure and the tire. During the deflated condition of the tire, the insert structure supports the tire and its load at a deflection that prevents excessively rapid deterioration of the tire while running in the deflated, run-flat condition.
U.S. Pat. No. 4,231,407 illustrates a protective liner for a tire having a tread portion and housing an inflatable tube, the liner having an elongated panel of puncture resistant material adapted to be extended circumferentially about the tube within the tire; and a pair of ridges borne by the panel extending in spaced, substantially parallel relation along the panel for embedded engagement with the interior of the tire to maintain selected alignment between the tread portion thereof and the panel.
U.S. Pat. No. 4,418,734 shows a safety support system in which an annular safety support of resilient foam material having an outer diameter less than the inner diameter of the tire is positioned around a rim and within the tire. The foam material has closed cells containing gas under pressure for supporting the tire in the deflated condition and expanding in an axial direction to press the bead portions against the bead seats of the rim. The safety support has beads and a fabric reinforced construction at a radially outer wall for controlling expansion beyond the radially outer diameter. A second reinforcing fabric ply may be provided at the radially inner wall for controlling expansion and facilitating field mounting of the safety support.
U.S. Pat. No. 5,099,900 describes a self-healing tire system containing a tire casing, a tacky sealant material, an inner tube, and anti-tack material. In one embodiment, either the surface of the inner tube or the inner surface of the tire casing is coated with the tacky sealant material. The surface of the sealant, the opposing surface, or both are coated with the anti-tack material. The anti-tack material renders the sealant non-tacky for a sufficient time so that the inner tube can be inserted and inflated. However, the anti-tack material allows the sealant surface to become tacky again thereby adhering to the tube and providing for sealing of the tube when it is punctured. In another embodiment, a release agent is contained between the sealant and the tire casing which facilitates removal of the sealant and tube from the tire casing.
U.S. Pat. No. 5,186,771 depicts a ring device for running with a flat tire on a vehicle wheel having a one-piece rim with a drop center. The ring device has articulated sectors and is housed inside the tire where it molds itself at least partially to the shape of the rim. The external surface of the ring is distant from the internal surface of the tread of the tire as long as the tire is in its normal operating condition.
U.S. Pat. No. 5,795,414 is directed to a tire assembly having a puncture resistant capability. The tire assembly includes an inner tube with an outer periphery having a plurality of protruding deflectable structures which are circumferentially continuous about the inner tube body. The deflectable structures have a cross-sectional appearance that is somewhat similar to miniature, hollow fingers. The tire assembly also includes a tire liner that has separator structures which are ridge-like in appearance and which are circumferentially continuous about the tire liner as well. The separator structures and deflectable structures are arrayed so as to mate with one another whereby the structure of the separator structures may assist the deflectable structures in maintaining their finger-like shape when under load. When a tack or other sharp object pierces the tire, it passes harmlessly between the deflectable structure and a separator structure, the deflectable structure being resiliently deflected to the side. A lubricant or insert between the separator structures and the deflectable structures assists in the frictionless deflecture of the deflectable structures. The invention is adaptable to tubeless tires as well.
The present invention is directed to a safety liner for a vehicle tire. The safety liner can be used with any tubeless pneumatic tire, and prevents the tire from completely collapsing and releasing the tire beads from the rim. When a tire rapidly deflates it can cause a loss of vehicle control. The present invention prevents rapid deflation by providing a liner which loses air slowly. The safety liner is inserted in the tire in a compressed state. One or more plugs are then removed which allow the safety liner to resiliently expand to its normal toroidal shape which partially fills the tire cavity. The safety liner may be removed from a worn out tire and reused. Or, if the safety liner is punctured, it may be repaired in the same manner as a tire.
A major advantage of the safety liner of the present invention, resides in the fact that one size liner can fit a variety of tire and rim models. For example, one size safety liner could be used with most 14 inch rims, another with most 15 inch rims, etc.
In accordance with a preferred embodiment of the invention, a safety liner for a vehicle tire includes a resilient hollow tube-like body in the form of a toroidal tube having at least one hole. At least one plug is selectively insertable into the at least one hole. The body is fabricated from a resilient material and has a normal toroidal shape. The body is compressible into a flattened substantially circular shape by a compressive force, and when the compressive force is removed, the body resiliently returns to its normal toroidal shape.
In accordance with an important aspect of the invention, when in its toroidal state, the body is shaped and dimensioned to circumferentially fit loosely inside the internal cavity of the vehicle tire. That is, the body fills most of the internal cavity of the vehicle tire.
In accordance with an important feature of the invention, the body includes abutting layers of rubber and tire casing fabric. The body is resilient, and after compression will slowly expand to its normal toroidal shape. The body is more rigid than a conventional tire tube.
In accordance with another important aspect of the invention, the hole is positioned so that (1) it is accessible when the safety liner is installed in the internal cavity of the vehicle tire, and (2) so that the hole is located adjacent to the tire bead during a blowout.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.